If you are experiencing darkness overspreading your eyes, it could be a temporary visual impairment or a symptom of a medical condition. Here are some general steps you can take:

  1. Stay calm: It is important to remain calm and not panic, as anxiety can worsen the situation.
  2. Check your surroundings: If you are in a dark room or area, turn on the lights or move to a well-lit area.
  3. Rest your eyes: Close your eyes and rest them for a few minutes. If you have been staring at a computer screen or a book for an extended period, take a break.
  4. Blink your eyes: Blinking can help to refresh your eyes and alleviate dryness.
  5. Seek medical attention: If the darkness persists, or if you are experiencing other symptoms such as eye pain, blurred vision, or a headache, it is important to seek medical attention from a qualified healthcare professional. They can assess your situation and recommend appropriate treatment or refer you to a specialist if necessary.

Remember, it is always better to err on the side of caution when it comes to your eyesight, as prompt treatment can prevent potential complications.